On Thu, Oct 21, 2021 at 06:04:13PM +0100, Marc Zyngier wrote:
> The MIPS GIC driver uses irq_cpu_online() to go and program the
> per-CPU interrupts. However, this method iterates over all IRQs
> in the system, despite only 3 per-CPU interrupts being of interest.
>
> Let's be terribly bold and do the iteration ourselves. To ensure
> mutual exclusion, hold the gic_lock spinlock that is otherwise
> taken while dealing with these interrupts.
Please consider a nitpick below. Other than that looks good:
Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx>
>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> ---
> drivers/irqchip/irq-mips-gic.c | 37 ++++++++++++++++++++++++----------
> 1 file changed, 26 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
> index 54c7092cc61d..45c83dd804a0 100644
> --- a/drivers/irqchip/irq-mips-gic.c
> +++ b/drivers/irqchip/irq-mips-gic.c
> @@ -381,24 +381,35 @@ static void gic_unmask_local_irq_all_vpes(struct irq_data *d)
> spin_unlock_irqrestore(&gic_lock, flags);
> }
>
> -static void gic_all_vpes_irq_cpu_online(struct irq_data *d)
> +static void gic_all_vpes_irq_cpu_online(void)
> {
> - struct gic_all_vpes_chip_data *cd;
> - unsigned int intr;
> + static unsigned int local_intrs[] = {
What about adding 'const' here?
-Sergey
> + GIC_LOCAL_INT_TIMER,
> + GIC_LOCAL_INT_PERFCTR,
> + GIC_LOCAL_INT_FDC,
> + };
> + unsigned long flags;
> + int i;
>
> - intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
> - cd = irq_data_get_irq_chip_data(d);
> + spin_lock_irqsave(&gic_lock, flags);
>
> - write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
> - if (cd->mask)
> - write_gic_vl_smask(BIT(intr));
> + for (i = 0; i < ARRAY_SIZE(local_intrs); i++) {
> + unsigned int intr = local_intrs[i];
> + struct gic_all_vpes_chip_data *cd;
> +
> + cd = &gic_all_vpes_chip_data[intr];
> + write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
> + if (cd->mask)
> + write_gic_vl_smask(BIT(intr));
> + }
> +
> + spin_unlock_irqrestore(&gic_lock, flags);
> }
>
> static struct irq_chip gic_all_vpes_local_irq_controller = {
> .name = "MIPS GIC Local",
> .irq_mask = gic_mask_local_irq_all_vpes,
> .irq_unmask = gic_unmask_local_irq_all_vpes,
> - .irq_cpu_online = gic_all_vpes_irq_cpu_online,
> };
>
> static void __gic_irq_dispatch(void)
> @@ -477,6 +488,10 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
> intr = GIC_HWIRQ_TO_LOCAL(hwirq);
> map = GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin;
>
> + /*
> + * If adding support for more per-cpu interrupts, keep the the
> + * array in gic_all_vpes_irq_cpu_online() in sync.
> + */
> switch (intr) {
> case GIC_LOCAL_INT_TIMER:
> /* CONFIG_MIPS_CMP workaround (see __gic_init) */
> @@ -663,8 +678,8 @@ static int gic_cpu_startup(unsigned int cpu)
> /* Clear all local IRQ masks (ie. disable all local interrupts) */
> write_gic_vl_rmask(~0);
>
> - /* Invoke irq_cpu_online callbacks to enable desired interrupts */
> - irq_cpu_online();
> + /* Enable desired interrupts */
> + gic_all_vpes_irq_cpu_online();
>
> return 0;
> }
> --
> 2.30.2
>
